OLEIC ACID AGAR 2OI 



9. Cool to 60 C., clarify with egg and filter. 



10. Weigh out 20 grammes saccharose and add to the contents 

 of the flask. 



u. Tube, and sterilise as for nutrient agar. 



Wood Ash Agar. 



-i. Measure 400 c.c. distilled water into a tared 2-litre flask. 



2. Weigh out 10 grammes agar and make into a thick paste 

 with 100 c.c. cold distilled water. 



3. Add this agar paste to the distilled water in the flask. 



4. Dissolve the agar by passing live steam through it, as in 

 preparing nutrient agar. 



5. Weigh out 5 grammes clean wood ash and place in a second 

 flask containing 200 c.c. distilled water with some sterile glass 

 beads: shake thoroughly in a mechanical shaker for ten minutes. 



6. Heat in steamer at 100 C., for thirty minutes. 



7. After removal from the steamer dry the outside of the flask 

 thoroughly, place it over a Bunsen flame and boil for one minute. 



8. Filter directly into the flask containing the melted agar 

 mixture. 



9. Weigh out 4 grammes maltose. Add to the contents of the 

 flask. 



10. Adjust the weight of the medium mass to the calculated 

 figure for one litre (1019 grammes) by the addition of distilled 

 water at 100 C. 



11. Replace the flask in the steamer for twenty minutes, cool 

 to 60 C., and clarify with egg and filter. 



12. Tube, and sterilise as for nutrient agar. 



Media for the Study of Special Bacilli. 



B. Acnes. 

 Oleic Acid Agar (Fleming). 



1. Measure out into a sterile stout glass bottle which already 

 contains about 10 sterile glass beads 



Ascitic fluid 250 c.c. 



2. Weigh out 



Oleic acid 25 grammes 



and add it to the ascitic fluid in the bottle. 



3. Emulsify evenly by shaking (either by hand or in a shaking 

 machine) for ten minutes. 



4. Liquefy and measure out into a flask 



Nutrient agar 750 c.c. 



then cool to 55 C. 



5. Mix the oleic acid emulsion with the agar. 



